Heartbleed flaw behind tax hack

Canada's tax-collection agency has been identified as a victim of the Heartbleed attack and the private information of about 900 people had been compromised. The breach allowed hackers to extract social insurance numbers, which are used for employment and gaining access to government benefits, and possibly some other data, the Canada Revenue Agency said.

It is the first confirmed report of hackers exploiting a flaw in OpenSSL to obtain actual data. A British parenting website Mumsnet, which claims more than 60 million monthly page views, said it had required all users to reset their passwords after a Heartbleed-related breach. It did not say whether any information had been taken. It is expected that there will be more attacks this week.

The Canada Revenue Agency said that police are investigating the attack, which occurred over a six-hour period. Forensic experts try to ascertain whether other data had been taken, a task that will be complicated because security experts say they believe that the Heartbleed bug allows attackers to steal data without leaving a trace.

The agency shut down access to its online services because of the bug.

Canadian authorities said that all government websites, including that of the Canada Revenue Agency, were back up as of Monday, with an updated and tested version of the OpenSSL software.